There is WiFi near my house which I use. It's an open WiFi network but it requires login and password once I connect to it by redirecting to login page. Everything is okay because I have them because I pay for it.
The funny thing is that in Ubuntu it doesn't work like in Windows. It does work fast but it "disconnects" me every 30 seconds or every minute by displaying "Unable to connect to the Internet" standard page. To be able to "reconnect" I have to reload a page about 20 times. Only after that it downloads it again and works fine for about 30 seconds.
By "disconnect" and "reconnect" I don't mean that I get disconnected from that WiFi net. It has a connection all the time I use the internet and that's fine. But the browser shows me (any browser in Ubuntu) the page of "Unable to connect to the Internet" and that's how it works.
In Windows I don't have that problem! The owner of WiFi doesn't know why it's happening.
What do I do about that?
It turned out that it required to wait for 30-60 seconds instead of reloading and after that I was able to download the page again. But the problem has not gone yet.